Se p 20 06 TYPE III AND SPECTRAL TRIPLES
نویسنده
چکیده
We explain how a simple twisting of the notion of spectral triple allows to incorporate type III examples, such as those arising from the transverse geometry of codi-mension one foliations. We show that the classical cyclic cohomology valued Chern character of finitely summable spectral triples extends to the twisted case and lands in ordinary (un-twisted) cyclic cohomology. The index pairing with ordinary (untwisted) K-theory continues to make sense and the index formula is given by the pairing of the corresponding Chern characters. This opens the road to extending the local index formula to the type III case.
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